import (
    "fmt"
    "encoding/json"
    "github.com/gorilla/mux"
    "log"
    "net/http"
)

type Calculate struct {
    Operand1  string   `json:"Operand1,omitempty"`
    Operand2 string   `json:"Operand2,omitempty"`
    Operator  string   `json:"Operator,omitempty"`
}

type Answer struct {
    Res string  `json:"Res,omitempty"`
}


func do_Calculation(w http.ResponseWriter, r *http.Request) {
    var cal Calculate
    var ans Answer
    fmt.Println("Request Reached")
    w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
    w.Header().Set("Content-Type", "application/json; charset=UTF-8")
    w.Header().Set("Access-Control-Allow-Origin", "*")
    w.WriteHeader(http.StatusOK)
    json.NewDecoder(r.Body).Decode(&cal)
    // my stuff
    // res := do_Operations(convertToFloat(cal.Operand1),convertToFloat(cal.Operand2),cal.Operator)
    // ans = Answer{Res: floattostrwithprec(res, 4)}
    json.NewEncoder(w).Encode(ans)
}



// main function to boot up everything
func main() {
    router := mux.NewRouter()
    router.HandleFunc("/calculate", do_Calculation).Methods("POST")
    fmt.Println("Server online at port :8000")
    log.Fatal(http.ListenAndServe(":8000", router))
}

var data = JSON.stringify({
  "Operand1": "2.6",
  "Operand2": "2.3334",
  "Operator": "+"
});

var xhr = new XMLHttpRequest();
xhr.withCredentials = true;

xhr.addEventListener("readystatechange", function () {
  if (this.readyState === 4) {
    console.log(this.responseText);
  }
});

xhr.open("POST", "http://127.0.0.1:8000/calculate");
xhr.setRequestHeader("Content-Type", "application/json");

xhr.send(data);